The invention relates to a chain driven front wheel drive and rear wheel steering bicycle. More particularly, the invention relates to a two wheeled vehicle wherein pedal or engine power is used to drive a fixed front wheel, and wherein steering of the vehicle is accomplished by pivoting the rear wheel.
By definition, a bicycle is a two wheel vehicle. Conventionally, a bicycle includes a frame, and two similarly sized wheels, which are inline with each other and with the frame. Pedals protrude to either side of the frame, which allow the rider to power the vehicle by means of a chain and sprocket arrangement, which links the pedals to the rear wheel. xe2x80x9cHandlebarsxe2x80x9d give the rider a firm hand-hold and allow the rider to steer the front wheel, which is generally located directly below the handlebars, and which is directly connected with the handlebars so that pivoting the handlebars also pivots the front wheel.
This arrangement is the most familiar configuration of a bicycle. It provides satisfactory transportation for the masses and in fact, literally billions of bicycles are in use worldwide. Virtually interchangeable bicycle components are readily available for bicycles having this overall configuration. However, the actual maneuverability, handling, and stability of the conventional bicycle leaves something to be desired.
In particular, the rear-wheel drive, front wheel steering arrangement of conventional bicycles makes the bicycle unstable in certain situations. For example, when the bicycle must stop suddenly to avoid an obstacle, the front wheel is charged with both steering the vehicle and providing the majority of the braking. Unfortunately the xe2x80x9ctire patchxe2x80x9d (that portion of the tire in contact with the road surface) has only a limited amount of frictional interaction with the road surface to accomplish both tasks. If the frictional xe2x80x9cabilityxe2x80x9d of the tire patch is exceeded, the wheel may skid uncontrollablyxe2x80x94resulting in a fall for the rider. This scenario is especially acute in a downhill, sudden-stop situation, and when traveling upon gravel, wet roads, or other less-than-favorable road surfaces.
In addition, the rear-wheel drive of conventional bicycles makes it difficult for the rider to overcome obstacles presented directly to the front tire. For example, rear wheel drive makes it especially difficult for the rider to travel up a curb or similar stationary object. Typically a rider is forced to xe2x80x9chopxe2x80x9d the front wheel onto the curb, since even considerable pedaling and subsequent torque at the rear wheel will not cause the front wheel to climb the curb. However, such practice compromises the stability of the rider and could easily result in a fall. Even worse, many riders are forced to dismount their bicycle and lift it over or onto the obstacle before they can continue riding.
Despite these clear disadvantages, the fact remains that the familiarity of the bicyclexe2x80x94that is: it""s seating position, pedaling angle, overall geometry, etc.xe2x80x94make it xe2x80x9chere to stayxe2x80x9d. What is desirable is to provide a solution which overcomes many of the clear disadvantages of the conventional bicycle, while preserving its familiarity to billions of riders worldwide.
U.S. Pat. No. 316,047 to Marble describes an early attempt at providing front wheel drive in a two wheeled vehicle. However, Marble uses a large front wheel for both drive and steering.
U.S. Pat. No. 6,068,279 to Dion describes an attempt to provide two-wheel drive by driving the front wheel in addition to the rear wheel. However, Dion still attempts to provide steering using the front wheel.
While these units may be suitable for the particular purpose employed, or for general use, they would not be as suitable for the purposes of the present invention as disclosed hereafter.
It is an object of the invention to produce a bicycle which provides superior maneuverability, handling, and stability when compared to prior art bicycles. Accordingly, a front wheel drive, rear wheel steering bicycle is described herein.
It is another object of the invention to provide a bicycle which is familiar and comfortable to riders of conventional bicycles. Accordingly, conventional geometry, rider position and posture, pedaling distances and angles, as well as physical demands upon the rider are preserved while implementing the improvements of the present invention.
It is a further object of the invention to provide a bicycle which may be inexpensively manufactured. Accordingly, by maintaining much of the standard bicycle configuration, the present invention can be constructed using mostly off-the-shelf components.
It is a further object of the invention to provide a drive system which can be employed in all types of chain driven, two wheel vehicles. Accordingly, the present invention can be implemented using various familiar bicycle configurations such as touring, racing, and mountain bicycles, as well as motorized bicycles such as motorcycles and mopeds.
To the accomplishment of the above and related objects the invention may be embodied in the form illustrated in the accompanying drawings. Attention is called to the fact, however, that the drawings are illustrative only. Variations are contemplated as being part of the invention, limited only by the scope of the claims.